Milky water exhaust question??

[JOHN COOKSON]

You can also feel the plugs. If one isn't hot it's not firing.
As you know if you suspect compression problems it's time for a compression test.
How clean is the prop?
I'm still of the opinion, until proven otherwise, that the increased water flow mentioned in post #1 is breaking KRAP loose in the cooling system and pushing it out the stern of the boat. Maybe an acid flush would be in order?

TRUE GRIT

[lat 64]

I will pose this question to all knowledgeable parties:

Do you think Barbara could have a blown or leaking head gasket that causes the air(we think it's air) in the exhaust water?
Would her higher temps be consistent with this theory?.
That would account for a bit more oily gunk in the exhaust water too, maybe.

Again, just grasping here,

Russ

[hanleyclifford]

I will pose this question to all knowledgeable parties:

Do you think Barbara could have a blown or leaking head gasket that causes the air(we think it's air) in the exhaust water?
Would her higher temps be consistent with this theory?.
That would account for a bit more oily gunk in the exhaust water too, maybe.

Again, just grasping here,

Russ

If I read it correctly the only change made was a reversal of the hoses on the strainer after which the symptoms appeared. If we operate on the assumption that the change caused the problem the only things we can look at are changed pressure and/or volume in the cooling water. Greater pressure could indeed reveal a bad head gasket. But first the air-in-the- strainer-discharge theory needs to be confirmed or rejected.

[Mo]

Might be unrelated...I'd be checking that all cylinders are firing first. The only time I've seen a whitish exhaust is a dead cylinder..raw fuel being pushed into exhaust stream. Easy to rule out. One of our members at our club had it once and checked fire to the plugs. Once he had done that he took it for granted that he had fire because the plugs were new and in the engine a month or so. Dud plug was the issue.

[blhickson]

I have not yet put the raw water strainer back the way it was. Just for clarification, the hoses remained the same, the strainer itself I turned 180 degrees) Instead, I'm going to 1) double check for airleaks around strainer parts/seals, 2) remove the gearbox cover and see what the oil looks like, and 3) check for spark on all 4 plugs.
I had planned to acid flush this spring but now might be better. I'm also looking up the symptoms of blown head gasket. Thanks and I'll keep you posted. Hope to get back to boat today after work.

[BunnyPlanet169]

One more variable

A note of caution in diagnosis: Barbara has a vee drive which means that the gearbox is also in the cooling circuit. I don't have any experience here...

[sastanley]

Barbara, Hold off on the acid flush..we don't need to introduce more "fixes" until we try to solve the problem at hand.

The issue with no power at higher RPM could be an indicator of a plug not firing..any chance you got the wires out of order or knocked one loose (check the distributor end of the wires too!) while messing with the strainer?

The "pull-a-plug" test is the next one I would do. Like Mo's friend, I've had bad plugs before, that I struggled and struggled with, and the solution was another $2 spark plug. Now, I simply replace them every season before spring start up.

[blhickson]

Gorgeous day here in Charleston! Must be 65 degrees.
I checked for water leaks and could tighten the clamps around the raw water I let thru hull quite a bit. The bilge underneath that was wet but is dry now with paper towel under for leak test.
I can see through the strainer container and I don't see any air bubbles whatsoever. Regardless, I took her apart and taped and used plumbers grease on fittings and refit the thing.
Checked all plugs with insulated glove and got plenty of shock still. All plugs changed rpms of engine when removing one at a time.
The exhaust volume has not changed. It still looks milky but in the bucket, the sample clears and has a floating sheen still of gasoline.
I have not searched for head gasket problems on this forum yet. I believe I'll go up to the marina office and see if they have any beer left from the weekend. The crew did not leave me any from Saturdays race.

[Dave Neptune]

Barbara, a little sheen is fine!!! The engine may be a bit rich and was probably cold too. Look to this later!!!!!!!!
Lets find the heat problems and not worry about the exhaust water being milky looking from air incursion.

Like Shawn said don't acid wash yet. Lets get the water flowing and find out where the restrictions are.
Does your engine have a bypass valve rigged on it? If so get it out and work on flow~the manifold fittings are the first suspect as stated before~once cleared, time to look to the block which will not be difficult to "read" once the t'stat is removed.

Once flow is established it will be time to determine an acid wash. Personally I would do a vinegar soak on the manifold when checking it, then the same with the block. This may shake some debris loose causing another restriction and it will probably show at the exit fitting again!

Dave Neptune

[tenders]

Bunny, don't worry, you aren't missing any nuances with the V-drive cooling system. Here's how it works: before raw water enters the suction side of the raw water pump, it runs through a metal tube that goes straight through the V-drive oil sump. That's it. There are barbed fittings on either side of the V-drive to allow the rubber intake hose to connect, and if the V-drive oil is hot, the tube cools it down.

If the hoses are clamped to the the barbs, which is almost certainly the case, the V-drive isn't part of this problem.

[lat 64]

...I believe I'll go up to the marina office and see if they have any beer left from the weekend. The crew did not leave me any from Saturdays race.

Time to have a "safety meeting" with the crew and explain, in no uncertain terms, their obligations and contributions to the smooth operation of a sailing vessel.

[blhickson]

I'm flushing my cooling system with vinegar. Is there any harm in marinading for 2 days or longer? Also, the thermostat has been working fine. Would it be asking for trouble to attempt to remove it for cleaning and testing? (I'm just curious about this thermostat testing-I've never done it). The t-stat upper housing bolts do not look new but they don't look terrible either. Been getting PB blaster on them to prep in case I actually do this. Curious as to the condition of the interior housing.

[Dave Neptune]

Barbara, letting it marinate is fine, for a day or two! You may nee to refresh depending on how dirty the insides are/were.
As far as the t-stat, it is best to soak with it out as it can reduce the filling with vinegar as it may not get past easily unless you have a bypass loop to allow the vinegar to fill her up good.
Testing the t'stat is easy. Just get a pan deep enough to immerse the t'stat and start the heat with a thermometer in the water.. It should start to open at the temp setting on the t''stat and be fully opened a bit above that temp. A good idea is to watch it close while monitoring the temps too.

Dave Neptune
.

[JOHN COOKSON]

The Lazy Cookson Method

Late model RWC engine.
Mix the acid in a 5 gallon bucket. Run a hose from the water pump intake to another 5 gallon bucket. Supply fresh water to this bucket from the marina water supply. Run the engine in gear until the theromstat is open. Close the valve on the bypass hose. Now all the water is going through not around the engine. Switch the hose to the bucket with the acid in it. After the acid has sat in the engine rinse it out by putting the hose back in the fresh water bucket.
Would be easier if you had a two way valve used to winterize.

TRUE GRIT

[blhickson]

What's "winterizing"?! LOL
I flushed all the vinegar out and there is maybe now 3 1/2 gals. per minute coming theu exhaust (1 gal more than before the vinegar flush). Exhaust water is definitely stronger projecting like sideways Vesuvius about 6 ft behind the boat. After 50 mins of running, water temp is barely 130. Exhaust cloudy but dissipates quickly in the water. Still some smoke.
Collected 2 gals as a sample and the water was slightly murky, brown red but fairly translucent. 3 tablespoons of floating grassy crap but no major chunks of metal or any rust flakes. Sounds good to me.
Regarding the t-stat, is it not opening? I don't see where the bypass hose is on my late model. If there's nothing "wrong" I don't want to invite trouble. Just swapping the input/output of the raw water filter is what got me here!
Thx for all your help! Engine running 1 hr at the slip and water temp is 140.